Though there are many variations, there are essentially only two ways to repair pipe: Open Excavation and Pipe Patching.

Open Excavation

Wastewater mainline damaged when a natural gas pipeline was installed.

In this process, excavation of surface material (in most cases, asphalt) and soils are removed to reach the affected pipe. Once this is achieved, the damaged section of pipe is removed and new pipe is installed. This method is not only costly, but in most cases is an inconvenience to citizens because traffic revisions and sometimes even entire road closures may be required. In addition, the equipment used is extremely loud, causing nuisance noise. The City avoids this method whenever possible; however, open excavation pipe repair may be required, depending on the size and severity of the damage.

Repaired wastewater mainline. Intact natural gas pipe.

Pipe Patching

In an effort to minimize traffic revisions and nuisance noise, The City of Redmond Wastewater Division has recently put a new pipe repair system into use, which requires no excavation. This particular repair process is a simple fiberglass-like patch kit. The process for installation requires the use of our CCTV truck. The patch is set with an inflatable tube that allows sewer to continue flow while the resin cures. This process is known as “Cure in Place” repair, has a minimal effect on traffic, and is much more cost effective than typical repair methods.

The video below shows a large separated joint in a wastewater pipe that required repair:

This video shows the large separated joint once it has been repaired by way of pipe patching: